Estimation of Infiltration Parameters and Manning Roughness with SIPAR_ID Software

Estimation of infiltration parameters is very difficult in furrow irrigation while they have very important effect in design and evaluation of surface irrigation systems. There are different methods for estimating infiltration parameters based on mathematical models such as SIPAR_ID model. SIPAR_ID model uses inverse solution to estimation of infiltration parameters and manning roughness. The objective of this study is to evaluate these models to estimate infiltration parameters in furrow irrigation. The study consisted of field experiments and numerical simulation. Field experiments were conducted in Zarand district of Iran in April 2012. Infiltration parameters and Manning roughness values were estimated with SIPAR_ID software. The estimated values were put into the WinSRFR software, and then the advance trajectory, flow depths in the upstream, and irrigation performance were simulated on each test furrow. The results showed that the simulated values with the WinSRFR software were in excellent agreement with the measured data. Therefore, the infiltration parameters and manning roughness estimated with SIPAR_ID software were reliable. Also that adequate and efficient irrigation can be obtained using closed-end furrows through a proper selection of inflow discharge and cutoff time.

Infiltration parameter; Irrigation performance; SIPAR_ID model; Manning Roughness